The present invention relates to a siphoning and/or discharge device for use in fluid transfer. An example of such a device is a food baster. Other examples include medicine droppers and pipettes. More specifically the present invention relates to a leak resistant siphoning and discharge device for handling hot fluids, and which employs an elastomeric valve to prevent leakage.
Basters are most commonly used in cooking to transfer hot juices from the bottom of a cooking pan back on to the meat/food being cooked in the pan to keep the meat/food moist while cooking. Commercially there have been few substantial improvements made to these devices due to the low cost nature of the device. But, the low cost basters do not adequately contain the liquid so as to effectively reduce leakage of liquid or partial solids that are drawn into the device for transfer to the desired location.
Basters come in a variety of sizes and shapes. Basters typically consist of a plastic, metal or glass elongated hollow body member and a resilient suction bulb, which is removably attached to the elongated hollow body member. The basters use suction, created by squeezing the resilient bulb, to draw liquid and partial liquids into the elongated hollow body member. It relies on the vacuum being held by the resilient bulb or the user to hold a constant pressure on the resilient bulb. To discharge the liquid and partial solids from the open end of the tube, the bulb is squeezed to increase the pressure of the air above the liquid and partial solids, expelling them.
Liquid and/or partial solids that are drawn up into the hollow member often leak out of the baster unintentionally. Also if the elongated hollow body member is tilted at a sufficient angle it allows the liquid contents to break vacuum, across the baster, causing the liquid to leak out of the elongated hollow body member. Leaks can also occur because the heat from the liquids causes the pressure of the air to build up in the bulb and force out some of the liquid or because something inadvertently places pressure on the bulb, such as a weighted object or a person inadvertently putting a hand or leaning on the bulb.
The disadvantage of leaking is that the liquid or partial solids are hot enough to burn users or people and pets that are nearby. The fats often contained in the liquid cause the fluid to burn to a greater extent than other hot liquids would. Also the leaking contents can spill on the floor, the counter, or the stove creating an unsightly mess, or worse, a safety hazard because of slip-and-falls or because an oven's heating element can ignite the liquid creating a fire hazard.
In addition, over time a resilient bulb stiffens and becomes less resilient decreasing its ability to pull a vacuum and to hold liquids and partial solids in the elongated hollow body member. The materials that are used are such that they deteriorate over time. Frequently cracks develop in the bulb, which again affects the ability to create suction in the elongated hollow body member. The deterioration can lead to inadequate sealing, which again causes problems with the baster holding vacuum. The junction between the bulb and the elongated hollow body member also deteriorates over time as the resilient bulb ages, losing elasticity. Many of the commercially available basters can be cleaned in dishwasher, but this can accelerate deterioration by assembling and disassembling the bulb and the elongated hollow body member. Also, the heat of the dishwasher can cause the elastomeric bulb to outgas elastomers and/or plasticizers and lose resilience and the ability to seal with the hollow body.
Further, the prior art basters typically cannot be tilted at an angle so as to be effective in easily and efficiently basting foods. The basters which attempt to solve the problems above present expensive solutions, and are not commercially cost effective. For example, where the basters have a primary valve located at the open tapered end of the tube, they tend to not seal adequately, are difficult to clean, or are complex in design and/or in operation.
The problems with the prior art basters are seen in the prior art patents. For example, U.S. Pat. No. 6,634,393 B2 to Jerry Porter discloses a baster where a primary valve is located at the outlet of the tube and the valve is a ball to close off the open end of the tube. This presents sealing problems. The weight of the ball assembly and liquid is the only means for the ball to return to its sealing position. The slippery nature of the liquid being drawn into the tube will tend to prevent the ball from sealing. Porter teaches adding a projection to activate or move the ball to allow liquid to be drawn in, but this also allows the user to “bump” or dislodge it causing an accidental discharge of liquid. Further, the air vent located near the bulb will also act as a means for liquid to run out when the baster is rotated to a horizontal plane. Furthermore the valve that Porter suggests is dependent on gravity to return to its sealing position. Changing the angle and orientation of the baster tube will limit the effectiveness of the sealing. Furthermore, the Porter baster does not rely on vacuum in the tube to keep the liquid suspended in the tube. The vacuum is released by means of the vent and relies on the mechanical valve in the open tip where the liquid is drawn into the baster tube to keep the liquid suspended in the tube. Since this mechanical valve is dependent on its orientation to maintain an adequate seal. The range of movement of this baster is very limited.
Porter, U.S. Pat. No. 6,634,393, teaches a baster which, in operation, vents air from an upper chamber through a hole placed in the top of the hollow tube. The function of this hole is to allow air to bleed off. Then, upon releasing the bulb a vacuum is created, by the bulb edge covering up the hole, but the vacuum has to be sufficient to overcome the leakage of the vent hole in order to draw the liquid into the tube. This function required the “pumping” action of the bulb due to the volume of the baster being greater than the bulb and the diminished effectiveness of the bulb to create a vacuum due to the vent hole. Due to the nature of an open hole in the top of the tube, the Porter baster does not appear to prevent liquids from coming into contact with the user and causing harm, if the baster is in a horizontal position.
Porter, U.S. Pat. No. 5,638,872, discloses a baster which includes a pair of valves where one valve is located at the tip of the tube and second valve is a one way valve. Porter does not claim it to be bi-directional or “open” in nature. This valve by description is automatic in nature. The description of this valve does not require the user to address it in order to make the baster function. The language describes a one-way air valve in the bulb that is intended to exhaust air only. When the bulb is released from its depressed state it creates vacuum. The valves that are described are pictured in the top surface of the bulb and are claimed to prevent liquid from escaping. Even though this feature is claimed there appears to be a lack of enough details to make them function. Porter appears to prefer having a hole in the upper portion of the tube with a rubber band around it to act as a valve.
Kummer, U.S. Pat. No. 5,514,118, teaches a medicine dropper which employs a valve between the barrel and the bulb to keep the fluid from filling the barrel further and thus limit the intake to the dosage amount. The valve is a float ball check valve where the ball comes against an annular rim 134 inside of the barrel to prevent further input into the barrel. Since the ball could not be removed for cleaning, it could be problematic in getting the dropper clean, and would appear to create another loose part.
Elastomeric valves have found use in preventing leakage in drinking cups for children, where they are employed in the so called “sippy cups”. Examples of these valves can be found in, for example, Freeman et al, U.S. Pat. No. 5,186,347; Brown, U.S. Pat. No. 4,991,745; and Fusco et al, U.S. Pat. No. 6,568,557.